1. Field of the Invention
The field of the present invention is reaction force type disk brakes, of a type which is mainly used for vehicles such as automobiles, and more particularly, improvements in a reaction force type disk brake comprising a first and a second friction pad facing opposite faces of a brake disk, respectively; a brake caliper provided with a first and a second clamping arm for clamping both the friction pads; opposite ends of the brake caliper in a circumferential direction of the brake disk being supported by a pair of slide-pin support portions of a fixed bracket through slide pins outside an outer periphery of the brake disk for sliding movements in a direction of a rotational axis of the brake disk; an urging member provided on the first clamping arm and having a center of urging at a central position of the first friction pad in the circumferential direction of the brake disk for urging the first friction pad to the brake disk; a pair of first braking-torque support portions mounted on the bracket for supporting a braking torque of the first friction pad; and a pair of second braking-torque support portions mounted on the brake caliper for supporting a brake torque of the second friction pad; wherein a pair at which fixing points of the bracket is fixed to a stationary member located at opposite sides of a first straight line which passes the center of urging and a center of rotation of the brake disk, the fixing points being disposed on a second straight line which crosses the first straight line at a location closer to the center of rotation with respect to the center of urging.
2. Description of the Prior Art
Heretofore, the disk brake of the type described above, is already known from, e.g., Japanese Patent Application Laid-open No. 22660/1977.
In such a disk brake, a single block protruded from the body of the bracket is commonly used by the first braking-torque support portions for supporting the braking torque of the first friction pad and the slide-pin support portions for supporting the slide pin.
In addition, the slide-pin support points, at which the slide pins are supported are arranged closer to the outer periphery of the brake disk than to a third straight line which is parallel to the second straight line and which passes the urging center.
In the above disk brake, when braking, since the braking torque effecting on the first friction pad is supported by the first braking-torque support portions, the first braking-torque support portions deflect in some degree If the single block is commonly used as in the conventional disk brake under such circumstances, the deflection of the first braking-torque support portions are directly transmitted to the slide-pin support portion. And as a result, a twist may arise between the slide pin and the slide-pin support portion, thereby deteriorating the smooth slide movement of the brake caliper which is undesirable.
Moreover, if the slide-pin support point is arranged as described above, a distance between the slide-pin support point and the fixing point becomes long. Therefore, when the braking torque effecting on the second friction pad has acted on the slide-pin support point through the second braking-torque support portion as well as the slide pin, a turning moment of relatively large magnitude is generated about the fixing point. This is undesirable for improving the durability of the bracket.